Photographic light source



June 30, 1964 N. GOLD ETAL 3,139,018

PHOTOGRAPHIC LIGHT SOURCE Filed Aug. 23, 1961 6 Sheets-Sheet l I NVENTO MM @4 2 BY W ATT'oRNEYs June 30, 1964 N. GOLD ETAL 3,139,013

PHQTOGRAPHIC LIGHT SOURCE Filed Aug. 25, 1961 6 Sheets-Sheet 2 June 1964 N. GOLD ETAL PHOTOGRAPHIC LIGHT SOURCE 6 Sheets-Sheet 3 Filed Aug. 23, 1961 June 30, 1964 N. GOLD ETAL 3,139,018

PHOTOGRAPHIC LIGHT SOURCE Filed Aug. 25, 1961 6 Sheets-Sheet 4 June 30, 1964 N. GOLD ETAL 3,139,018

PHOTOGRAPHIC LIGHT SOURCE Filed Aug. 23, "L961 6 Sheets-Sheet 5 INVENEORS BYMZQM kfifis I June 30, 1964 GOLD TA 3,139,018

PHOTOGRAPHIC LIGHT SOURCE Filed Aug. 25, 1.961 6 Sheets-Sheet 6 FIG.8

FIG.9

INVEN ORS 51 W ATTORNEYS United States Patent This invention relates to sources of illumination for exposing photosensitive sheet materials and, particularly, to light sources useful in photographic document copying apparatus.

The present invention is concerned with a source of illumination especially adapted for use in photographic document copying apparatus of the type including means for superposing an original document to be copied with a photosensitive sheet and moving the document and photosensitive sheet in superposition past the light source for exposing the photosensitive sheet to produce an image therein. Light sources useful in this type of apparatus are generally elongated so as to extend from side to side of the document and are held in fixed position while the original document and superposed photosensitive sheet are moved at a constant predetermined rate past the light source for uniformly exposing successive areas of the photosensitive sheet. Light sources of this type employed heretofore have usually comprised tubular fluorescent lamps together with some means, such as filters or special apertures, for insuring uniformity of illumination throughout the length of the lamp.

An object of the invention is to provide a photographic light source which is elongated, emits light substantially uniformly throughout its length, and comprises an incan descent lamp as a'source of light.

Another object of the invention is to provide a source of illumination as described for use in a photographic document copying apparatus including means for moving a photosensitive sheet and an original document in superposition along a predetermined path, relative to and past the source of illumination. .7

Further objects of the invention are: to provide a source of illumination for photographic document copying apparatus as described, comprising an elongated lightconducting member extending transversely of the direction of movement of the photosensitive sheet through the apparatus, an incandescent lamp at one end of the lightconducting member and novel means for insuring uniformity of light emission throughoutthe length of said member; to provide a source of illumination as described in which the light-conducting member is an elongated rod having a substantially uniform circular cross section throughout its length, polished end and. peripheral surfaces, and a plurality of contiguous axial grooves in its peripheral surface, at least one ofthe groovesextending from end to end 0f the portion of the rod emitting light.

for exposing the photosensitive sheet, and other grooves commencing at successively greater distances from the end of said rod at which the lamp is located; and to provide a light source as described in which the light-conducting rod functions as a retracting element for directing light, emanating from said rod, toward said photosensitive sheet.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the apparatus possessing the construction, combination of elements and arrangement of parts which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following "Ice detailed description taken in connection with the accompanying drawings wherein:

FIGURES 1 and 2 are perspective views of document copying apparatus embodying the invention;

FIG. 3 is a sectional View of the apparatus of FIGS. 1 and 2, the section being taken along a plane substantially midway between the sides of the apparatus;

FIG. 4 is a view similar to FIG. 3 showing the components of the apparatus in an inoperative position in which the components are spaced apart to permit loading of sheet materials into the apparatus;

FIG. 5 is a perspective view of components of the apparatus shown with the outer housing removed;

FIG. 6 is a fragmentary perspective view, partially in section, of a light source employed in the document copier;

FIG. 7 is an enlarged sectional view taken along the line 7--7 of FIG. 6;

FIG. 8 is a fragmentary plan view illustrating, in detail, one of the components of the light source of FIG. 6;

FIG. 9 is a view similar to FIG. 5 illustrating components of the apparatus; and

FIG. 10 is an electrical diagram showing the electrical components of the apparatus.

The document copying apparatus incorporating the invention and described herein is of the type designed to be completely portable and hand-operated so as to require no external power source, permitting it to be used anywhere. The operation of the device is quite simple and involves the manual advancement of the photosensi tive sheet through the apparatus which, in turn, drives a generator for supplying electric current to a lamp for exposing the photosensitive sheet material. The photo sensitive sheet is supplied, exposed, and processed entirely within the apparatus and may be relatively fast, since all the operations are performed in a light-free environment. Because the apparatus employs photosensitive material which is comparatively sensitive to light, as opposed to the usual document copying apparatus in which the photosensitive material is handled in the light and must be relatively insensitive, the source of illumination for exposing the photosensitive material need not be large, and requires very little power for its operation. It is this arrangement which permits the light source to be powered by a generator driven in response to manual advancement of the photosensitive sheet through the apparatus. I

Reference is now made to the drawings wherein there is illustrated one form of photographic document copying apparatus embodying the invention. This apparatus comprises a housing, designated 10, for mounting and enclosing the components of the apparatus. Housing 10 comprises an upper housing section 12 and a lower housing section 14 pivotally secured to one another at a hinge 16 located at one end (termed the rear end) of the housing. The two housing sections are pivotable between the closed or operative position shown in FIGS. 1 through 3, in which the components of the apparatus are inoperative relation, and the open or inoperative position shown in FIG. 4, in which the two housing sections are located apart from one another to permit loading of photographic materials into the apparatus in preparation for use.

Upper housing section 12 includes an upper wall 18 including means defining an inlet passage 20 and exit passage 22 through which an original document to be copied can be, respectively, introduced into and fed from the apparatus. Inlet passage 20 is defined by convergent walls designated, for purposes of description, as a forward wall 24, a rear wall 26 and side walls 28. Exit passage 22 is similarly defined by a forward wall 36, rear wall 32 and side walls 34. The housing sections I ,r atus, are withdrawn from the housing.

' opening 36 is defined by a forward end wall 38 on lower include portions defining a withdrawal opening 36 at the forward end of the housing through which photographic sheet materials, including copiesproduced by the appa- Withdrawal housing section 14 and a forward end'wall 40 on upper housing section 12. Forward end wall 38 extends upwardly at an angle toward the front of the housing and forward end wall 40 extends downwardly at an angle toward the front of the housing and then rearwardly at an angle toward the rear of the housing where the lower edge of forward end wall 4% cooperates with the upper edge of forward end wall 38 to' define withdrawal opening 36.

Housing includes upper side walls 42 on upper housing section 12 and lower side walls 44 on lower housing section 14. Lower housing section 14 also' includes, a bottom wall 46 on which are mounted feet 48 which serve to support the apparatus, and which are preferably formed of a material, such as rubber, having a high coeflicient of a friction for preventing the apparatus from sliding on the surfaceon which it is supported during use.

The operative components of the document copying apparatusare mounted on support members or chassis carried within housing It) on the upper and lower housing sections. These support members include a lower chassis or frame 59 comprising a base plate 52 and side plates .54 and 56 extending upwardly from the base plate which rests on bottom wall% of lower housing section 14. An upper chassis or frame 58 is provided comprising side plates 60 and 62 which may be joined by connecting rods .64. Side plates 54 and 56 are provided with hinge extensions 66 and side plates 60 and 62 are similarly provided with hinge extensions 68. The hinge extensions of the upper and lower chassis or frames are pivoted at hinge 16 on a common hinge pin 70. Upper chassis 58 is secured within upper housing section 12 so that the upper chassis and housing section pivot together about hinge pin 7 0. i

The apparatus includes an intermediate chassis or frame 72 comprising a pair of arms 74 pivotally mounted adjacent their ends onside plates 54 and 56 adjacent the forward .ends of the side plates. Arms 74 are pivotally mounted at studs 76 secured in side plates 54 and 56 so i that intermediate chassis 72 may be pivoted between the operative position, shown'in FIG. 3, to the inoperative position of FIG. 4, which permits loading of photographic materials into the apparatus.

The document copying'apparatus of the invention is designed to produce copies of original documents by a photo graphic process involving the exposure of a photosensitive sheet and the treatment of the exposed photosensitive sheet with-a fluid to produce a transfer image in a second or image-receiving sheet which is superposed with the exposed photosensitive sheet during treatment of the latter. The photosensitive sheet, herein designated 77," preferably comprises a photosensitive silver halide carried on a suit able support. The silver halide may be in the form of a gelatin emulsion and the support may comprise any of the conventional film base materials, paper being preferable because of its inexpensiveness. Exposure of the photosensitive material may be of one of two different types, i.e., reflex or direct. Direct exposure of the photosensitive material involves exposure of the silver halide to light transmitted through the original to the photosensitive material, and-is useful when the original light, then reflex" exposure is used and this involves trans- Following exposure, the photosensitive material is treated with a fluid in conjunction with a second or imagereceiving sheet, herein designated '78, superposed with the photosensitive sheet to form a transfer image on the image-receiving sheet. silver halide diffusion transfer-reversal process distin guished by the fact that it is an essentially dry process, in which the fluid effecting the processing is confined between the sheets, obviating the necessity for tanks of fluid in which the sheets are immersed.

In this type of-photograp-hic transfer process, the photosensitive and second sheets are superposed and a fluid is distributed between the sheets by advancement of the superposed sheets in superposition between a pair of pressure-applying members. The two sheets are retained in superposition for a predetermined periodduring which a silver halide developer'in the processing fluid reduces exposed silver halide to silver and unexposed silver halide is converted to a soluble complex which is transferred by diffusion to the image-receiving sheet where it is reduced to silver to form a positive transfer image. The imagereceiving sheet may include an image-receptive layer carried on a suitable support such as paper, or it may function as a support for a layer in which the image is formed. For examples of processes of this type and materials useful therein, reference may be had to US. Patents Nos;-

2,543,181, issued February 27, 1951, and 2,662,822, issued December 15, 1953, both in the name of Edwin H. Land.

The apparatus comprises means for holding a supply of photosensitive sheet 77, preferably in the form of an elongated web or strip of suflicient length to make a large number of copies. ventional spool 80 and means on side plates 54 and 56 of lower chassis St) for mounting the spool at itsends for pivotal movement between the side plates within the rearmost portionof housing 10. Arms 74 of intermediate chassis 72 are provided with means for mounting a second spool 82 on which is coiled a supply of imagereceiving sheet 78'substantially equal in length and width to photosensitive sheet 77. The supply of second sheet 78 on spool 82 is enclosed within housing lit at the forv ward end of the housing.

In accordance with the invention, the document copying apparatus includes novel and improved means for vironment prior to and during exposure and processing and the use of a fast photosensitive material makes it possible to employ a light source which is not required tobe as intense as that necessary if the photosensitive sheet material were to be handled in the light.

The two sources of illumination embodying the inven tion are basically the same and each is elongated, extends transversely of the path of movement of the photosensitive sheet, and is designed to emit substantially uniform illumination throughout a length at least equal to the-width of the area of the original to be copied. Each light source comprises an elongated bar or rod 84 preferably cylindrical and having a substantially uniformcross section mitting the actinic light through the photosensitive sheet to the surface (to be copied) of the original which reflects some of the light back to the photosensitive material, further exposing the photosensitive material to form a developable image therein throughout its length. Rod 84 is provided with polished,

end and peripheral surfaces and is formed of a transparent light-conducting material such as glass or one of the organic plastics, acrylic resins sold under the trademarks Lucite (E. I. du Pont de Nemours & Company) and Plexiglas (Rohm & Haas Co.) being particularly suited for this purpose. Rod 84, in the form shown, has the Image formation is effected by a This means comprises a con-' property of conducting light introduced at one end through the length of the rod to the other end by internal reflection, and is caused to emit light throughout its length by the provision on its peripheral surface of a plurality of scratches in the form of contiguous axial grooves 85. Grooves 85 are preferably V-shaped in cross section and each comprises two surfaces having mat finishes. The grooves, in aggregate, provide a diffusely reflecting surface which reflects light, transmitted by the bar, radially through the bar so that the light is emitted from the peripheral surface of the bar diametrically opposite grooves 85. The faces or surfaces of eachgroove may, for example, be arranged at approximately a 90 angle with respect to one another and, in one embodiment of the rod, each groove occupies about 5 of the peripheral surface of the rod.

In the preferred form shown, six of the grooves extend from end to end of that portion of rod 84 from which light is emitted for exposing the photosensitive sheet. Since the intensity of light transmitted from one end of the rod toward the other decreases as a function of the distance from the end of the rod at which the light is introduced, the grooves are arranged to provide for uniformity of light emission throughout the length of the light-emitting portion of the rod. In accordance with the invention, this is accomplished by providing a succession of grooves which commence at successively greater distances from the end of the rod at which light is introduced, with successive grooves being disposed on opposite sides of the full length grooves and previous partial length grooves, as shown in FIG. 8. l The distances of the 1 starting points of the successive grooves from the end of the light-transmitting portion of the rod has been de termined empirically for various forms of light-transmitting rods and grooves. For example, for making copies of documents 8 /2 inches in width, a diameter Lucite rod, approximately in length and having polished peripheral and end surfaces was employed. The rod was provided wtih six full length grooves commencing onehalf inch from a polished end of the rod, each groove occupying approximately 5 of the surface of the rod and having mat surfaces disposed at approximately 90 with respect to one another. Therod was provided with twelve partial length grooves commencing at successively greater distances from the end of the rod. The following table gives the distances between the starting points of successive grooves:

1.000 inch .730 inch .950 inch .695 inch .900 inch .660 inch .855 inch .630 inch .810 inch .600 inch .770 inch .570 inch All of the grooves, of course, extend to the end of the light-emitting portion of the rod furthest from the source of illumination.

It is contemplated that a light source, .such as an incandescent lamp, could be provided at each end of the rod, in which case the starting and terminal points of the partial length grooves would be located at successively greater distances from both ends of the rod.

The grooves, as previously noted, reflect light diametrically through the rod toward and through a portion of the peripheral surface of the rod disposed diametrically. opposite the groove. This arrangement has the added advantage of causing the rod itself to function as a lightrefracting element or cylindrical lens for focusing the light emitted from the rod so that the light is more concentrated at the photosensitive sheet.

Each of rods 84- is enclosed in a cylindrical tube 86 formed of a material such as metal which is opaque to light actinic to the photosensitive material, and is provided with an axial slot 88 equal in length to the lightemitting portion of the rod, i.e., the full length grooves.

6 The internal diameter of tube 86 is just slightly greater than the external diameter of rod 84 so that the tube closely engages the rod, and slot 88 is disposed diametrically opposite grooves 85 with the center line of the slot diametrically opposed to the median line of the full length grooves. One of the sources of illumination comprising a rod 84 and tube 86 is mounted on upper housing section 12 and the other is mounted on lower housing section 14. The photosensitive sheet and original are guided in superposition between the two sources of illumination so that the photosensitive sheet may be subjected to either a reflex or direct exposure. One of tubes 86 is mounted at one end in side plate 56 with its other end section, designated 90, extending through an opening in side plate 54. The other tube 86 is similarly mounted with one end secured in side plate 62. and its other end section, also designated 90, extending through an opening in side plate 60.

The sources of light transmitted by the rods comprise incandescent lamps 92, each mounted within end section 90 of a tube 86 adjacent the end of the rod 84 contained within the tube. Each lamp 92, which can be quite small since the luminance requirements need not be great, is mounted in a reflector 94 carried on an end cap 96 secured to end section 90 of the tube. Tubes 86 and rods 84 contained therein are mounted with their axes substantially parallel and with slots 88 facing one another, and are employed alternatively to subject the photosensitive sheet to either a direct or reflex type of exposure.

The guide means of the invention includes a cylindrical tube 98 formed of a material such as glass or organic plastic capable of transmitting light actinic to the photosensitive material. Tube 98 has an inside diameter greater than the outside diameter of tube 86 and is mounted in surrounding relation to the tube 86 which is mounted on upper chassis 58. A pair of elongated guide rolls 100 and 102 are provided mounted for rotation on and intermediate side plates 54 and 56. Guide rolls 100 and 102 are positioned with their axes substantially parallel with one another and with the axes of bars 84 and tubes 86, and are located for engaging tube 98 at positions spaced from one another around the periphery of the cylindrical surface of tube 98. Guide rolls 100 and 102 preferably include surface portions having some resiliency and a high coeflicient of friction, materials such as rubber being suitable for this purpose. A backing roll 104 is provided mounted for rotation on and intermediate side plates 60 and 62 in position for urging tube 98 against guide rolls 100 and 102.

Photosensitive sheet 77 is conducted from spool 80 between guide roll 100 and tube 98 around a portion of the cylindrical surface of tube 98 and between guide roll 102 and tube 98. Slots 88 in tube 86 are positioned for transmitting light from bars 84 for exposing the portion of the photosensitive sheet supported by tube 98 intermediate guide rolls 108 and 102, and the sources of illumination are designed to be used selectively and one at a time for exposing the photosensitive sheet as it is advanced around the portion of tube 98 between guide rolls 100 and 102 past slots 88 in tubes 86.

During exposure of photosensitive sheet 77, an original document, designated 106 in FIG. 3, is superposed with the photosensitive sheet between the latter and tube 98. The original is introduced through passage 20 and means are provided for sealing the passage against the admission of light and guiding and feeding the original into superposition with photosensitive sheet 77 at the bite of guide roll 100 and tube 98. In the form shown, the light-sealing and feeding and guiding means comprise a pair of inlet feed rolls 108 mounted for rotation in juxtaposition with their axes substantially parallel, within housing 10, on and between side plates 60 and 62. Inlet feed rolls 108 include resiliently deformable surfaces and are positioned with the bite of the feed rolls located in align- V 7 ment with the inner end of passage 20 in position for engaging original 106 and advancing the original toward the bite of tube 98 and guide roll 100. The inlet feed rolls engage theoriginal along a line lying in a plane substantially tangent to the surface of tube 98 at a line at least closely adjacent the line of contact between tube 98 and guide roll 100. At least one of inlet feed rolls 108 is driven for advancing original 106 through passage 20 into the bite of tube 98 and guide roll 100 between the tube and photosensitive sheet 77. A light-sealing element 110 is provided dependent from rear wall 26 and extending downwardly to the rear of the rearmost inlet feed roll 108 and forwardly to a position adjacent the bite of tube 93 and guide roll 100 for insuring against exposure of the photosensitive sheet to light transmitted through passage As a means for feeding original 106 from the housing through passage 22 following exposure of the photosensitive sheet in superposition with the original, there are provided a pair of outlet feed rolls 112 mounted for rotation in juxtaposition and with their axes parallel on and-between side plates 60 and 62. The construction of outlet feed rolls 112 is similar to that of inlet feed rolls 108 and the outlet feed rolls are positioned with the bite of the rolls locatedat the inner end of exit passage 22 in position for engaging the original along a line lying in a plane substantially tangent to both tube 93 and guide roll 102. The document copying apparatus is designed for copying originals which are substantially flat and tend to assume a planar configuration so that as an original 106 is advanced from between the bite of tube 98 and guide roll 102, the leading edge of the original tends to move in a plane tangent to tube 9%, guide roll 102 and outlet feed rolls 112 so as to enter the bite of the outlet feed rolls and becomes engaged thereby. At least one of the outlet feed rolls is driven for advancing the original from the housing through exit passage 22. Additional light-sealing means are provided for exit passage 22 and,

in the form shown, comprise a light-sealing element dependent from forward passage wall 30 extending around the forwardmost outlet feed roll 112 to a position adjacent guide roll 102. Light-sealing element'114 performs the additionalfunction of aiding in guiding the leading end of the original from between tube 98 and guide roll 102 into the bite of outlet feed rolls 112. The housing includes an inner wall 116 extending between forward passage wall 24 and rear passage wall 32. Mounted on inner wall 116 is a light-sealing element 118 having a first dependent portion 120 extending downwardly between the forwardmost inlet feed roll 108 and tube 98 and a second dependent portion 122 extending downwardly from a position adjacent the rearmost outlet feed roll 112 to a position adjacent tube 98. Second dependent portion 122 cooperates with the lower portion of light-sealing element 114 to provide a passage for guiding the original from between tube 18 and guide roll 102 into the bite of outlet feed rolls 112.

As previously noted, the exposed photosensitive sheet 77 is processed to produce a positive copy of the original by superposing the'photosensitive sheet, with a second or print-receiving sheet 78 and distributing a processing A fluid between the superposed sheets to form a sandwich.

The means in the apparatus of the invention for perform- -ing this processing comprise a pair of pressure-applying rolls 124 and 126, roll 124 being mounted for rotation on 82 around roll 124 into superposition with the photosensitive sheet between rolls 124 and 126. Mounting of spool 82 and pressure-applying roll 124'on intermediate chassis 72 permits the photosensitive and image-receiving sheets to'be threaded in superposition between the pressure-applying rolls.

In the form of document copying apparatus shown, the processing fluid for each exposed area of the photosensitive sheet is provided on the photosensitive sheet in the form of an elongated mass extending from side to side of the exposed area of the sheet near the leading edge of the exposed area, that is, on the "portion of the photosensitive sheet extending'between guide roll 102 and the bite of pressure-applying rolls 124 and 126. Advancement of the photosensitive and second sheets in superposition between the pressure-applying rolls causes this mass offluid to be distributed between the sheets toward the trailing end of the exposed area of the photosensitive sheet. It is contemplated that the processing fluid required for each exposed area of the photosensitive sheet, in order to produce a positive copy of the image-receiving sheet, will be supplied in an elongated tubular container very much like a conventional drinking straw. This container, designated 130 in FIG. 3, includes a cavity of substantially uniform cross section approximately equal in length to the width of the exposure area of the photosensitive sheet and filled with the processing fluid. Both ends of the container are sealed to prevent escape of the fluid and the admission of air into the container, and one end, termed the trailing end, is constructed so as to be- I come unsealed in response to the generation of hydraulicpressure within the fluid, to form a discharge mouth preferably equal in area to the cross-sectional area of the fluid-filled cavity through which the fluid contents of the container are discharged. Containers of this type, their construction and function are described in detail in the I copending U.S. application of Edwin H. Land, Serial No.

I pressure-applying rolls.

erative positionshown in FIG. 3. Rolls 124 and 126 are located adjacent guide roll 102, androll 126 is mounted for limited movement toward and away from roll 124, spring means 128 being provided for biasing roll 126 toward roll 124. Photosensitive sheet 77 extends from between tube 98 and guide roll 102 between rolls 124 and issued July 31, 1962.

The apparatus includes means permitting the container to be introduced into the apparatus so that it extends across and adjacent the portion of photosensitive sheet 77 extending between guide roll 102 and the bite of the This means is shown and described in detail in the copending US. application, Serial No. 133,483, filed August 23, 1961 in the name of Edwin" H. Land et a1. and comprises a tapered opening 136 in lower side wall 44. Mounted within the housing in alignment with opening 136 is a channel-shaped guide member 138 which extends from the tapered opening into the housing past the-edge of the photosensitive sheet for supporting and guiding container 130 into the housing into a position extending across and adjacent the photosensitive sheet. The container is introduced into the housing until the leading end thereof is located adjacent the margin of the photosensitive sheet furthest from opening 136 and the leading end of the-fluid-filled cavity is located adjacent the lateral edge of the exposure area. The container'is then compressed at a position in the region of the edge of the exposure area closest opening 136 and simultaneously withdrawn from the apparatus through opening 136. This causes the leading end of the container to become unsealed and the fluid contents of the container to be ejected therefrom in the form of a uniformly distributed elongated mass. extending across the portion of the photosensitive sheet extending between guide roll 102 and the pressure-applying rolls.

Means are provided for compressing the container, as described, during its withdrawal in order :to cause ejection of the fluid from the container. This means com prises a turned-up curve lip on the inner end of guide member 138 and a corresponding juxtaposed lip-on the inner end of a channel-shaped pressure member 144 mounted for limited pivotal movement inside guide member 138 in such a way that the guide member and pressure member cooperate to form a tube through which the straw-shaped pod is introduced and withdrawn. A manually operable push button 146, mounted in a recess in upper wall 18 and side wall 42, is provided for pivoting pressure member 144 so that the lip on member 138 is urged toward the lip on member 144 to apply compressive pressure to the container. Push button 146. actuates a plunger rod extending inwardly from upper side wall 42 and bearing against pressuremember 144 for pivoting the pressure member toward guide member 138 when button 146 is depressed.

.The photosensitive and print-receiving sheets comprising the sandwich formed by pressure-applying rolls 124 and 126, are required to remain in superposition during a predetermined imbibition (processing) period, during which the sandwich is retained in the dark and at the end of which the sandwich may be moved into the light and the sheets separated. The apparatus includes means for transporting the sandwich through the housing within a light-tight environment and then guiding the sandwich from the housing through withdrawal opening 36. This means comprises a pair of rolls 156 and 158 mounted in juxtaposition within the housing adjacent and in closing relation to withdrawal opening36. Both of rolls 156 and 158 preferably comprise surface layers of a compliant material having a high coefficient of friction, rubber being desirable for this purpose. Roll 158 is mounted for rotation on lower chassis 50 closely adjacent forward end wall 38. Roll 156 is mounted for rotary movement at its ends on arms 160, in turn pivotally mounted on intermediate chassis 72. Torsion springs 162 are provided for biasing arms 160 so as to urge roll 156 toward and into engagement with roll 158 when the apparatus is in the operative position shown in FIG. 3. Mounting of roll 156 on intermediate chassis 72 permits roll 156 who spaced apart from roll 158, when the apparatus is in the open position shown in FIG. 4, thereby permitting the photosensitive and second sheets to be threaded between pressure-applying rolls 124 and 126 and between rolls 156 and 158. Tabs 164 are provided on the lower portion of arms 74 of intermediate chassis 72 for engaging arms 160 and acting as a stop for pivotal movement of arms 160 when the intermediate chassis is pivoted to an open position.

The document copying apparatus of the invention is intended, as previously noted, to be manually operated by grasping and pulling on a portion of the sandwich comprising the photosensitive and second sheets projecting from the housing through withdrawal passage 36. To operate the apparatus to make a copy, the operator introduces a container 130 into the housing through opening 136, depresses button 146 and holds the button depressed while withdrawing the container fromthe housing. This provides an elongated mass of fluid on the portion of the photosensitive sheet extending between guide roll 102 and pressure-applying rolls 124 and 126; thereupon the operator introduces an original 106 into passage until the leading end of the original is at the bite of inlet feed rolls 108, whereupon the operator grasps the end portions of the photosensitive and second sheets extending through passage 36 and pulls the photosensitive and image-receiving sheets to advance them through the apparatus. It is during this advancement that the original -is fed into superposition with the photosensitive sheet between the latter and tube 98, the .photosensitive sheet is exposed and the exposed area of the photosensitive sheet is advanced in superposition with an area of the imagereceiving sheet between the pressure-applying rolls to distribute the fluid and form a sandwich which is advanced from the pressure-applying rolls to rolls 156 and 158 and thence from the apparatus through withdrawal passage 36. The apparatus includes a transmission driven by frictional engagement of one of the sheets with one of the rolls and connected with the various components of the apparatus for effecting the introduction and ejection of the original and the exposure of the photosensitive sheet. In the form shown in FIG. 9, the transmission is driven by frictional engagement of the photosensitive sheet with roll 158, and comprises a sequence of engaged torque-transmitting members such as toothed or friction gears, the latter being shown as the preferred form because many of the friction gears which are required to coact are on different chassis.

The transmission includes a first friction roll 166 keyed to the shaft on which roll 158 is mounted, and a second (idler) friction roll 168 mounted on side plate 56 of lower chassis 50 in frictional engagement with friction roll 166. Each of outlet feed rolls 112 is connected to a friction roll 170, the latter being frictionally engaged with one another and one of friction rolls 170 being frictionally engaged with second friction roll 168,,the latter transmitting torque to friction roll 170 with which it is engaged for rotating the output feed rolls. Torque is transmitted to the inlet feed rolls 108 through an idler friction roll 172 engaged with one of friction rolls 1'70 and with one of a second pair of friction rolls 174 coupled with inlet feed rolls 108. Only one of outlet feed rolls 112 need be driven so to feed the original from the apparatus when the leading edge of the original has been fed from the bite of tube 98 and guide roll 102 into the bite of the outlet feed rolls. The other friction roll 170 would then merely function as an idler for transmitting torque from the driving friction roll 170 to idler friction roll 1'72.

The document copying apparatus of the invention is designed to be operated manually without the need for an outside source of electrical power; and power for the light sources, i.e., lamps 92, is supplied manually in conjunction with advancement and processing of the sheet materials. Current for the lamps is supplied by a direct or alternating current generator, designated 176, connected to the transmission through a friction drive roll 178 and an idler friction roll 180 keyed to the same shaft as idler friction roll 172. Generator 176 is shown as being mounted on upper wall 18 of the upper housing section intermediate inlet and exit passages 20 and 22. Reference is now made to FIG. 10 of the drawings for a circuit diagram showing the electrical connections between the generator and lamps 92 and one system for determining which of the two lamps is to be employed for exposure and the intensity of the lamp. One output terminal of the generator is grounded in the chassis and the other output terminal is connected to a rheostat 182 having separate parallel windings each connected in series with one of lamps 92. The construction of the rheostat is such that only one of the windings is employed at any time so that only one of the lamps is illuminated. A control knob 184 is provided on the rheostat exteriorly of the housing so that the lamps may be employed selectively and the intensity thereof may be controlled.

The exposure of the photosensitive sheet and the duration of the'processing of the photosensitive and imagereceiving sheets is a function of the rate of advancement of the sheets through the apparatus and, accordingly, the rate of movement of the sheets" through the apparatus must be controlled. For this purpose the apparatus is provided with a governor designated 186. Governor 186 may be of a conventional mechanical type mounted, for example, coaxially with generator 176 on the same shaft or, as in the form shown, may be mounted apart from a generator and connected to the transmission through a friction drive roll 188 frictionally engaged with idler friction roll 180. The governor functions to limit the speed of the transmission and thereby control the output of the generator and, hence, intensity of lamps 92; and also controls the rate at which the photosensitive sheet is moved through the apparatus so that the period during which any portion of the photosensitive sheet is subjected to exposure to light from rods 84 is substantially preand the image-receiving sheet from pressure-applying rolls 124 and 126 to. rolls 156 and 158 is also controlled so that the processing or imbibition period is of a predetermined constant duration.. p d

When making a copy of a document, the portion of the sandwich projecting from the apparatus through opening 36 is pulled until. a predetermined length of the two sheets is advanced through the apparatus. This lengthis approximately equal to the length of the document being copiedplus sufficient extra sheet material to advance the portion of the sandwich containing the copy completely from the apparatus through opening 36. A metering mechanism may be provided in the. apparatus and coupled with the transmission for metering the length of the sheets advanced through the apparatus for each eopy or the sheet materials may be provided with some indicia visible to the operator toindicate when a sufficient length'of the sheet materials has been withdrawn through the apparatus. The aforementioned'extra length of sandwich is obviously at least equal to the sheet path length between guide roll 102 and opening 36and this extra length of sandwich may, in one form of the apparatus, serve to trap and retain any excess processing fluid which is distributed between the sheets beyond the trailing edges of the exposed area of the photosensitive sheet and image-receiving area of the second sheet.

When a length of sandwich containing a copy of an original has been advanced from the apparatus through withdrawal opening 36, this length of sandwich is then severed in the region of the withdrawal opening from the portion of the sandwich remaining within the apparatus. Severance of the sandwich is accomplished with the aid of a cutter bar 190 mounted on arms 192 which are pivotally mounted on upper chassis 53. Arms 19?.

extend throughslots in forward end Wall 40 and cutter bar190is located exteriorly of the forward end walle and this section of the sandwich functions as a leader which may be grasped after the sandwich has been severed therefrom by tearing the sandwich against edge 194 ofthe cutter bar which, incidentally, may be sharpened to facilitate this operation. A torsion spring (not shown) may beprovided for urging the cutter bar'countercloekwise (viewing FIG. 3) into the upper position shown in the drawings, at which position the operator may grasp the section of the sandwich extending through opening- 36-for pulling the sheets through the apparatus to produce a copy of an original document.

Since certain changesmay be made in theabove apparatus without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

L1. In photographic document copying apparatus comprising means for moving a light-sensitive sheet along a predetermined path in superposition with an original document to be copied, in combinationwith said means, an

elongated source of illumination positioned adjacent said path of movement of said light-sensitive sheet and extendtion, said source comprising an elongated transparent rod for conducting light .by internal reflection from one end toward the other; and a lamp mounted adjacent saidone end surface, the peripheral surface of said rod being provided w1th a plurality of. scratches in the form of contiguous axial grooves, at least one of said grooves.extend peripheral surface for transmitting light from ing throughout the length of an intermediate section of said rod employed to emit light for exposing said lightsensitive sheet, other of said grooves commencing at successively greater distances from the end of said section closest said lamp with succeeding grooves located on oppositesides of said one groove and all of said grooves extending to the end of said section furthest'from said lamp, said rod being positioned with the grooved portion 5 of said peripheral surface facing away from said path of movement of said light-sensitive sheet whereby'light from said lamp conducted by said rod is reflected from said grooved portionof said peripheral surface through said rod to be emitted therefrom at a portion of said peripheral surface opposite said grooved portion of said peripheral surface. a

2. The photographic apparatus of claim 1 wherein said source of illumination includes an opaque tubedisposed in surrounding relationto'said rod, said tube including a lengthwise slot disposed adjacent the portionof said pe= ripheral surface opposite said grooved portion of said said light-sensitive sheet. e

- 3. The photographic apparatus of claim 2 wherein an end section of said tube projects beyond'the end' of said rod at said one end surface, and said lamp is mounted within said end section of said tube.

References Cited in the file of this patent UNITED STATES PATENTS i 2,188,821 Rylsky Jan. 30, 1914 2,437,555 Rees Mar. 9,- 1948 2,732,778 Limberger Jan; 31, 1956 2,901,632 Stava et al. Aug. 25, 1959 2,909,857 Wilson Oct. 27, 1959 2,996,969 Kaufman Aug. 22,

said rod'to ,7 j 

1. IN PHOTOGRAPHIC DOCUMENT COPYING APPARATUS COMPRISING MEANS FOR MOVING A LIGHT-SENSITIVE SHEET ALONG A PREDETERMINED PATH IN SUPERPOSITION WITH AN ORIGINAL DOCUMENT TO BE COPIED, IN COMBINATION WITH SAID MEANS, AN ELONGATED SOURCE OF ILLUMINATION POSITIONED ADJACENT SAID PATH OF MOVEMENT OF SAID LIGHT-SENSITIVE SHEET AND EXTENDING TRANSVERSELY OF THE DIRECTION OF MOVEMENT OF SAID SHEET ALONG SAID PATH FOR SUBSTANTIALLY UNIFORMLY EXPOSING SUCCEEDING PORTIONS OF SAID SHEET AS THE LATTER IS MOVED ALONG SAID PATH RELATIVE TO AND PAST SAID SOURCE OF ILLUMINATION, SAID SOURCE COMPRISING AN ELONGATED TRANSPARENT ROD FOR CONDUCTING LIGHT BY INTERNAL REFLECTION FROM ONE END TOWARD THE OTHER; AND A LAMP MOUNTED ADJACENT SAID ONE END SURFACE, THE PERIPHERAL SURFACE OF SAID ROD BEING PROVIDED WITH A PLURALITY OF SCRATCHES IN THE FORM OF CONTIGUOUS AXIAL GROOVES, AT LEAST ONE OF SAID GROOVES EXTENDING THROUGHOUT THE LENGTH OF AN INTERMEDIATE SECTION OF SAID ROD EMPLOYED TO EMIT LIGHT FOR EXPOSING SAID LIGHTSENSITIVE SHEET, OTHER OF SAID GROOVES COMMENCING AT SUCCESSIVELY GREATER DISTANCES FROM THE END OF SAID SECTION CLOSEST SAID LAMP WITH SUCCEEDING GROOVES LOCATED ON OPPOSITE SIDES OF SAID ONE GROOVE AND ALL OF SAID GROOVES EXTENDING TO THE END OF SAID SECTION FURTHEST FROM SAID LAMP, SAID ROD BEING POSITIONED WITH THE GROOVED PORTION OF SAID PERIPHERAL SURFACE FACING AWAY FROM SAID PATH OF MOVEMENT OF SAID LIGHT-SENSITIVE SHEET WHEREBY LIGHT FROM SAID LAMP CONDUCTED BY SAID ROD IS REFLECTED FROM SAID GROOVED PORTION OF SAID PERIPHERAL SURFACE THROUGH SAID ROD TO BE EMITTED THEREFROM AT A PORTION OF SAID PERIPHERAL SURFACE OPPOSITE SAID GROOVED PORTION OF SAID PERIPHERAL SURFACE. 